Random Sampling

In random sampling, each member of a population has an equal chance or probability of getting selected.

This process is an unbiased representation of the total population in which each subject is selected independently of other members of the population.

Example:

Population: the Daily closing price of some stock starting from 1st Jan 2015 till 31st July 2015. This will include all historical data, since the first day in Jan 2015 up till the end of July 2015.

Sample: From the population of 7-months data (nearly 150 data points), randomly select 21 data points.